2-6 External Control
External control mode may be selected by turning DIP switch # 2 (remote) ON.
The position of DIP switch # 3 determines whether bit-parallel or RS-232C be used for external control.
(1) Bit-parallel (DIP Switch # 3: OFF)
The15-pin D-sub connector on the back panel may be used for light control and ON/OFF control.
The rotary dials on the front panel are enabled when pin #9 (INT/EXT) is OFF. When pin #9 is ON,
light control and ON/OFF control are based on the following input status conditions.
Control Bit Configuration
Bit
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12
Construction (LSB) Light intensity data (0 to FF) (MSB) INT/ENT /WR
OFF/
ON
TRIG
(2) Signal Logic
Data and control bits are negative logic bits (active LOW: maximum light intensity date when all bits are
LOW).
Use a driver IC, open collector, or other device to output the signal.
(3) External/manual control selector
This selector is used to switch to external control mode. (The rotary dials are disabled in this mode.)
External Control Mode Selection - B9 (INT/EXT)
Note: External control mode cannot be selected if DIP switch # 2 is OFF.
(4) Data Entry Sequence
Note: Data can be written in external control mode, but not in manual control mode.
(i) The light intensity data (B1 to B8) outputs in negative logic (maximum light intensity date with
all bits LOW).
(ii) It outputs the write bit (data written in 1 ms max.).
NPN open collector ON
Manual
External
Tst
Thd
Tpw
Write light intensity data
Tst
≥
100
µ
s
Tpw
≥
1 ms
Thd
≥
100
µ
s
B1 to B8
(8 bits)
Write B10
(/WR)
NPN open collector ON